The RRS feels cheap inside, and out. The Terrain response system is nice; however, I despise it. I prefer a regular low range transfer case with locking differentials or something like the 4ETS system. The RR is bigger, better engineered, and it looks 100x better inside and out. The BMW M62 V8 is no longer used in the 2006 HSE, the Jaguar 4.2L 300hp V8 is now used. The front diff issue is a known issue, but I have yet to hear of it in my area, or experience it. My friend has a 2003 RR HSE with 94,000 miles on it, and he has had 0 issues with it.
As for the RR being heavier then the LR3 and RRS, yea, who cares? I obviously am not looking at LR's for their incredible acceleration and cornering abilities.
If LR stops producing the MKIII (which I hear is very possible) I will certaintly look else where. The MKIII is a master piece in my eyes. The looks, the performance, the interior, everything is just perfect! It could not have been done any better. The only thing I wish for is that aftermarket manufactures start making mods for the MKIII. Not bling bling wheels, but off-road mods aka useful mods.